Add QNetworkProxy::usesSystemConfiguration() accessor

Allow to check programmatically whether using the system proxy settings
is enabled. To implement this the QSystemConfigurationProxyFactory is
replaced by an explicit boolean in QGlobalNetworkProxy.

Change-Id: I52231b4ffc890b085bcd1739acf93c97bdb18eb5
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@theqtcompany.com>

4 files changed, 55 insertions, 103 deletions

diff --git a/src/network/kernel/kernel.pri b/src/network/kernel/kernel.pri
index 8f37e28669..005f000c25 100644
--- a/src/network/kernel/kernel.pri
+++ b/src/network/kernel/kernel.pri
@@ -18,7 +18,6 @@ HEADERS += kernel/qtnetworkglobal.h \
            kernel/qnetworkinterface.h \
            kernel/qnetworkinterface_p.h \
            kernel/qnetworkproxy.h \
-           kernel/qnetworkproxy_p.h \
            kernel/qurlinfo_p.h
 
 SOURCES += kernel/qauthenticator.cpp \
diff --git a/src/network/kernel/qnetworkproxy.cpp b/src/network/kernel/qnetworkproxy.cpp
index bb1a7d0d8b..94719e9c2d 100644
--- a/src/network/kernel/qnetworkproxy.cpp
+++ b/src/network/kernel/qnetworkproxy.cpp
@@ -224,7 +224,6 @@
 
 #ifndef QT_NO_NETWORKPROXY
 
-#include "private/qnetworkproxy_p.h"
 #include "private/qnetworkrequest_p.h"
 #include "private/qsocks5socketengine_p.h"
 #include "private/qhttpsocketengine_p.h"
@@ -256,10 +255,12 @@ public:
 #ifndef QT_NO_HTTP
         , httpSocketEngineHandler(0)
 #endif
-    {
 #ifdef QT_USE_SYSTEM_PROXIES
-        setApplicationProxyFactory(new QSystemConfigurationProxyFactory);
+        , useSystemProxies(true)
+#else
+        , useSystemProxies(false)
 #endif
+    {
 #ifndef QT_NO_SOCKS5
         socks5SocketEngineHandler = new QSocks5SocketEngineHandler();
 #endif
@@ -280,6 +281,24 @@ public:
 #endif
     }
 
+    bool usesSystemConfiguration() const
+    {
+        return useSystemProxies;
+    }
+
+    void setUseSystemConfiguration(bool enable)
+    {
+        QMutexLocker lock(&mutex);
+        useSystemProxies = enable;
+
+        if (useSystemProxies) {
+            if (applicationLevelProxy)
+                *applicationLevelProxy = QNetworkProxy();
+            delete applicationLevelProxyFactory;
+            applicationLevelProxyFactory = nullptr;
+        }
+    }
+
     void setApplicationProxy(const QNetworkProxy &proxy)
     {
         QMutexLocker lock(&mutex);
@@ -288,6 +307,7 @@ public:
         *applicationLevelProxy = proxy;
         delete applicationLevelProxyFactory;
         applicationLevelProxyFactory = 0;
+        useSystemProxies = false;
     }
 
     void setApplicationProxyFactory(QNetworkProxyFactory *factory)
@@ -299,6 +319,7 @@ public:
             *applicationLevelProxy = QNetworkProxy();
         delete applicationLevelProxyFactory;
         applicationLevelProxyFactory = factory;
+        useSystemProxies = false;
     }
 
     QNetworkProxy applicationProxy()
@@ -318,6 +339,7 @@ private:
 #ifndef QT_NO_HTTP
     QHttpSocketEngineHandler *httpSocketEngineHandler;
 #endif
+    bool useSystemProxies;
 };
 
 QList<QNetworkProxy> QGlobalNetworkProxy::proxyForQuery(const QNetworkProxyQuery &query)
@@ -339,10 +361,19 @@ QList<QNetworkProxy> QGlobalNetworkProxy::proxyForQuery(const QNetworkProxyQuery
 
     if (!applicationLevelProxyFactory) {
         if (applicationLevelProxy
-            && applicationLevelProxy->type() != QNetworkProxy::DefaultProxy)
+            && applicationLevelProxy->type() != QNetworkProxy::DefaultProxy) {
             result << *applicationLevelProxy;
-        else
+        } else if (useSystemProxies) {
+            result = QNetworkProxyFactory::systemProxyForQuery(query);
+
+            // Make sure NoProxy is in the list, so that QTcpServer can work:
+            // it searches for the first proxy that can has the ListeningCapability capability
+            // if none have (as is the case with HTTP proxies), it fails to bind.
+            // NoProxy allows it to fallback to the 'no proxy' case and bind.
+            result << QNetworkProxy(QNetworkProxy::NoProxy);
+        } else {
             result << QNetworkProxy(QNetworkProxy::NoProxy);
+        }
         return result;
     }
 
@@ -717,7 +748,8 @@ quint16 QNetworkProxy::port() const
 
     Setting a default proxy value with this function will override the
     application proxy factory set with
-    QNetworkProxyFactory::setApplicationProxyFactory.
+    QNetworkProxyFactory::setApplicationProxyFactory, and disable the
+    use of a system proxy.
 
     \sa QNetworkProxyFactory, applicationProxy(), QAbstractSocket::setProxy(), QTcpServer::setProxy()
 */
@@ -1465,6 +1497,17 @@ QNetworkProxyFactory::~QNetworkProxyFactory()
 {
 }
 
+/*!
+    \since 5.8
+
+    Returns whether the use of platform-specific proxy settings are enabled.
+*/
+bool QNetworkProxyFactory::usesSystemConfiguration()
+{
+    if (globalNetworkProxy())
+        return globalNetworkProxy()->usesSystemConfiguration();
+    return false;
+}
 
 /*!
     \since 4.6
@@ -1472,23 +1515,16 @@ QNetworkProxyFactory::~QNetworkProxyFactory()
     Enables the use of the platform-specific proxy settings, and only those.
     See systemProxyForQuery() for more information.
 
-    Internally, this method (when called with \a enable set to true)
-    sets an application-wide proxy factory. For this reason, this method
-    is mutually exclusive with setApplicationProxyFactory(): calling
-    setApplicationProxyFactory() overrides the use of the system-wide proxy,
-    and calling setUseSystemConfiguration() overrides any
-    application proxy or proxy factory that was previously set.
+    Calling setUseSystemConfiguration(\c{true}) will reset any proxy or
+    QNetworkProxyFactory already set.
 
     \note See the systemProxyForQuery() documentation for a list of
     limitations related to the use of system proxies.
 */
 void QNetworkProxyFactory::setUseSystemConfiguration(bool enable)
 {
-    if (enable) {
-        setApplicationProxyFactory(new QSystemConfigurationProxyFactory);
-    } else {
-        setApplicationProxyFactory(0);
-    }
+    if (globalNetworkProxy())
+        globalNetworkProxy()->setUseSystemConfiguration(enable);
 }
 
 /*!
@@ -1504,7 +1540,7 @@ void QNetworkProxyFactory::setUseSystemConfiguration(bool enable)
 
     If you set a proxy factory with this function, any application
     level proxies set with QNetworkProxy::setApplicationProxy will be
-    overridden.
+    overridden, and usesSystemConfiguration() will return \c{false}.
 
     \sa QNetworkProxy::setApplicationProxy(),
         QAbstractSocket::proxy(), QAbstractSocket::setProxy()
diff --git a/src/network/kernel/qnetworkproxy.h b/src/network/kernel/qnetworkproxy.h
index fc919a24a6..8fcb7e33cf 100644
--- a/src/network/kernel/qnetworkproxy.h
+++ b/src/network/kernel/qnetworkproxy.h
@@ -213,6 +213,7 @@ public:
 
     virtual QList<QNetworkProxy> queryProxy(const QNetworkProxyQuery &query = QNetworkProxyQuery()) = 0;
 
+    static bool usesSystemConfiguration();
     static void setUseSystemConfiguration(bool enable);
     static void setApplicationProxyFactory(QNetworkProxyFactory *factory);
     static QList<QNetworkProxy> proxyForQuery(const QNetworkProxyQuery &query);
diff --git a/src/network/kernel/qnetworkproxy_p.h b/src/network/kernel/qnetworkproxy_p.h
deleted file mode 100644
index 733d8436d0..0000000000
--- a/src/network/kernel/qnetworkproxy_p.h
+++ /dev/null
@@ -1,84 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2009 David Faure <dfaure@kdab.net>
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtNetwork module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef QNETWORKPROXY_P_H
-#define QNETWORKPROXY_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API. It exists purely as an
-// implementation detail. This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include <QtNetwork/private/qtnetworkglobal_p.h>
-
-#ifndef QT_NO_NETWORKPROXY
-
-QT_BEGIN_NAMESPACE
-
-class QSystemConfigurationProxyFactory : public QNetworkProxyFactory
-{
-public:
-    QSystemConfigurationProxyFactory() : QNetworkProxyFactory() {}
-
-    virtual QList<QNetworkProxy> queryProxy(const QNetworkProxyQuery& query)
-    {
-        QList<QNetworkProxy> proxies = QNetworkProxyFactory::systemProxyForQuery(query);
-
-        // Make sure NoProxy is in the list, so that QTcpServer can work:
-        // it searches for the first proxy that can has the ListeningCapability capability
-        // if none have (as is the case with HTTP proxies), it fails to bind.
-        // NoProxy allows it to fallback to the 'no proxy' case and bind.
-        proxies.append(QNetworkProxy::NoProxy);
-
-        return proxies;
-    }
-};
-
-QT_END_NAMESPACE
-
-#endif // QT_NO_NETWORKINTERFACE
-
-#endif
-